Compress Video
Reduce your video file size with quality control. Free, in your browser, no uploads.
.mp4, .mov, .avi, .mkv · up to 100 MB
Why compress video
Fewer megabytes, same visual quality
Total privacy
Your video never leaves your device. FFmpeg.wasm processes everything locally, no server uploads.
CRF quality control
The CRF parameter gives you precise control over the trade-off between visual quality and file size.
Universal compatibility
Output in H.264 + AAC, compatible with any player, social network, or video platform.
Instant after first load
The FFmpeg engine downloads once and is cached. All subsequent compressions start immediately.
How it works
Three steps, no hassle
Upload your video
Drag and drop or select your video file. No registration, no format restrictions.
Choose quality
Adjust the CRF parameter: lower values = higher quality, higher values = more compression.
Download the result
The compressed video is processed in your browser. Download with one click.
FAQ
Got questions?
It depends on the CRF setting: CRF 23 = high quality with ~30% size reduction, CRF 28 = balanced with ~50%, CRF 35 = maximum compression with ~70% reduction.
CRF (Constant Rate Factor) is the H.264 quality parameter. Lower value = better quality and larger file; higher value = more compression with possible quality loss.
CRF 18-23 is visually lossless. Above 28, degradation may be noticeable on detailed content such as text or complex backgrounds.
Processing is limited by device memory. On most modern devices you can process between 100 MB and 500 MB without issues.
FFmpeg.wasm processes at approximately 2-5x real-time on modern devices. A 1-minute video takes between 12 and 30 seconds.
H.264 is used for video and AAC for audio — the codecs with the broadest universal compatibility across players, social networks, and streaming platforms.
Video compression: H.264/AVC encoding, CRF rate control, video compression for social media, web performance optimization, email attachment limits
Modern video compression is based on block-based encoding and inter-frame prediction. H.264 (also known as AVC, Advanced Video Coding) has been the dominant standard since its publication in 2003 by the JVT (Joint Video Team). Unlike GIF, which compresses each frame almost independently, H.264 only stores the differences between consecutive frames using motion vectors, enabling size reductions of 10 to 50 times compared to uncompressed sequences with virtually identical visual quality.
The CRF (Constant Rate Factor) parameter in x264 is a scale from 0 to 51 where 0 is lossless and 51 is maximum compression. The default value of 23 provides a good balance for most content. In practice, values between 18 and 28 are most commonly used: below 18 the size increase is significant without perceptible visual gain; above 28 artifacts start appearing on edges and detailed textures. CRF is a constant quality metric, meaning the bit rate varies according to the complexity of each scene.
Digital distribution platforms impose size limits that make compression necessary: WhatsApp limits videos to 16 MB, many email clients reject attachments over 25 MB, and platforms like Instagram and TikTok reward videos with a good quality-to-size ratio with greater organic reach. Compression also improves web performance: Google PageSpeed considers video optimization as a Core Web Vitals factor when video is used as a page background or primary content.